Fixed a bug where errors thrown from performLockedOperation would c…

…ause a 'lock leak'!

ts/semaphore.ts

@@ -133,11 +133,19 @@ export class Semaphore {
 
 		let lock: SemaphoreLock = await this.getLock();
 
-		let result: T = await operation();
-
-		lock.release();
-
-		return result;
+		try {
+
+			return await operation();
+
+		} catch (error: any) {
+
+			throw error;
+
+		} finally {
+
+			lock.release();
+
+		}
 
 	}